RESUMO
Bacteria of the genus Azospirillum include several plant associated bacteria which often promote the growth of their host plants. Although the host range of Azospirillum brasilense Sp7 is much wider than its close relative Azospirillum lipoferum 4B, it lacks the ability to efficiently utilize D-glucose for its growth. By comparing the genomes of both the species, the genes of A. lipoferum 4B responsible for conferring D-glucose utilization ability in A. brasilese Sp7 were identified by cloning individual or a combination of genes in a broad host range expression vector, mobilizing them in A. brasilense Sp7 and examining the ability of exconjugants to use D-glucose as sole carbon source for growth. These genes also included the homologs of genes involved in N-acetyl glucosamine utilization in Pseudomonas aeruginosa PAO1. A transcriptional fusion of the 5 genes encoding glucose-6-phosphate dehydrogenase and 4 components of glucose phosphotransferase system were able to improve D-glucose utilization ability in A. brasilense Sp7. The A. brasilense Sp7 strain engineered with D-glucose utilization ability showed significantly improved root colonization of rice seedling. The improvement in the ability of A. brasilense Sp7 to colonize rice roots is expected to bring benefits to rice by promoting its growth. KEY POINTS: ⢠Genes required for glucose utilization in Azospirillum lipoferum were identified. ⢠A gene cassette encoding glucose utilization was constructed. ⢠Transfer of gene cassette in A. brasilense improves glucose utilization and rice root colonization..
Assuntos
Azospirillum brasilense , Azospirillum , Oryza , Azospirillum brasilense/genética , Azospirillum brasilense/metabolismo , Glucose/metabolismoRESUMO
Human adenovirus (HAdV-2) is considered a common agent of respiratory tract infection in the human, especially in children. Virus infection is believed to modify host cell expression necessary for its replication and therefore cell proteome can reflect the changes of specific cellular pathways during infection. This study aims to identify differentially expressed proteins of A549 cells in response to HAdV-2 infection using a label-free liquid chromatography-high-resolution tandem mass spectrometry strategy (LC-MS/MS) at 24 and 48 hpi. A total of 248 and 216 proteins were deregulated by 1.35-fold at 24 and 48 hpi, respectively. Among them, 155 were upregulated at 24 hpi and 86 at 48 hpi, whereas 93 and 130 were downregulated at 24 and 48 hpi, respectively. The identified proteins were involved in different pathways as energy, transcription, protein synthesis, cytoskeleton, rescue and defense, cell cycle, DNA processing, transportation, and metabolism. Glycolytic pathway and histone deregulated proteins were further confirmed by chemical testing and immunofluorescence, respectively. The results suggest that the identified proteins influenced HAdV-2 infection in the context of viral replication and propagation. This study complement proteomic data obtained from previous studies and reinforce the understanding of the relationship between HAdV and host cell.